Various mechanisms for supporting computer keyboards below the desktop surface are known. Smeenge, in U.S. Pat. No. 4,616,798, entitled “Adjustable Support for CRT Keyboard”, discloses a mechanism which includes first and second sets of parallel, equal length, articulating arms that link first and second brackets with a keyboard platform at one end and a sliding bracket plate attached beneath the desktop at the opposite end. The parallel arms are pivotally connected to the platform and bracket plate and move in a vertical plane to maintain the keyboard support platform in a generally horizontal position regardless of the position of the platform relative to the desktop. During storage of the keyboard support platform, the arms pivot so that the platform is then lowered to a retracted position below the level of the desktop. The arms may be locked in a fixed orientation by a threaded handle or lever which inhibits pivotal motion of one or both arms.
Other keyboard support constructions are illustrated in U.S. Pat. Nos. 4,625,657; 4,632,349; 4,706,919; 4,776,284; 4,826,123; and 4,843,978. Each of these described designs uses a parallel arm type mechanism that allows adjustment of the height of the keyboard support. U.S. Pat. Nos. 6,233,031; 6,523,797 and 6,601,812 also disclose designs with parallel arms that allow adjustment of the height of the keyboard support platform. McConnell, U.S. Pat. No. 5,037,054, entitled “Adjustable Support Mechanism for a Keyboard Platform”, shows a keyboard support mechanism that uses non-parallel arms to support the keyboard platform.
These various prior art mechanisms are useful in conjunction with standard desk equipment.
Thus, there has developed a need for improved keyboard support mechanisms for storage of a computer keyboard and which permit easy movement of the platform to a desired level. Additionally, another desired characteristic for such mechanisms is to provide a stable surface for the keyboard. Further desired is an improved mechanism which safely and securely locks a keyboard platform in a desired orientation and which permits easy release or unlocking of the platform from a fixed orientation.